The invention relates to multiband antennas and particularly to a multiband unitary antenna unit for receiving television signals and for transmitting and receiving 2-way communication signals like in mobile cellular telephones.
With the increasing popularity of cellular telephones, a need has arisen for antennas to be used on automobiles and the like vehicles. Previously, television antennas have been provided for automobiles in a winged, ornamental housing as shown in Des. Pat. No. 245,778 wherein a dipole antenna folded in the shapes of both wings. Cellular telephone antennas have typically included rectilinear elements commonly referred to as 3 dB antennas. With the use of a television and a cellular phone in one vehicle, the need for multiple antennas on the vehicle has arisen. The mounting of more than one antenna on a vehicle gives a cluttered appearance. While it is desirable to eliminate multiple antennas on a vehicle, it is not always simple or practical from a technical and aesthetic view point.
A folded antenna consisting of a plurality of dipoles connected end to end in a generally J-shaped pattern, commonly referred to as a folded Franklin antenna, has been known and used typically for business (emergency, police, etc.) and marine bands and vertically polarized.
Accordingly, an important object of the invention is to provide a multi-element antenna capable of operating at multiple bands from a compact unitary housing for vehicular use.
Another object of the invention is to provide a multiband antenna unit which may be used for receiving television and 2-way communication.
Another object of the invention is to provide a compact vehicle antenna capable of efficiently operating in the television and cellular telephone frequency bands in a unitary housing without interference from one another.